Brush



June 15, 1965 T. F. GARY 3,188,672

BRUSH Filed Dec. 18, 1963 d d e 94in l e d LDJLZ/I $12M. WWW? [LL UL Hi i AL TQ TV INVENTOR. imam 4A Y BY g TTORNEY United States Patent 3,188,672 BRUSH Timothy F. Gary, Rensselaer, N.Y., assignor to Johnson 8; Johnson, a corporation of New Jersey Filed Dec. 18, 1963, Ser. No. 331,579 18 Claims. (Cl. 15167) The present invention relates to brushes having jointed bristle-carrying sections or segments, and although applicable to brushes of various types, the invention is particularly useful for toothbrushes, including electric toothbrushes.

It has been proposed to provide a toothbrush with an articulated head made up of separate, equally spaced bristle-carrying sections which are interconnected by flexible webs of uniform thickness. These webs are generally in the form of a spring insert or inserts which are separate from the sections. The bristle-carrying sections so articulated permit the head to bend so that the brush bristles can conform substantially to the contour of the teeth, thereby entering the spaces between the teeth for proper cleaning action.

The brushes having articulated heads as described are made by injection or compression molding the bristlecarrying sections over the spring insert or inserts which form the flexible webs. During the molding operation, the spring insert or inserts may be displaced accidentally, thus resulting in a defective toothbrush.

Moreover, since the portions of the spring insert between the bristle-carrying sections of the head of the brush are substantially of uniform length, width, and thickness, and since, during use of the toothbrush, the bending stresses on these portions of the spring insert increase as the distances of these portions from the outer end of the toothbrush head increase, the head does not bend uniformly, and the insert portions do not suffer material fatigue to the same extent.

One object of the present invention is to provide a new and improved toothbrush of the articulated type which can be manufactured at comparatively low cost with substantially uniform accuracy, thereby materially reducing the number of rejects.

Another object of the present invention is to provide a new and improved toothbrush having a head of the articulated type which has a comparatively long life.

A further object of the present invention is to provide a new and improved toothbrush of the type referred to and which has connecting webs between bristle-carrying sections which are designed to control the bend and material fatigue in these portions in accordance with a predetermined pattern.

Another object of the present invention is to provide a new and improved toothbrush of the articulated type which does not have the drawbacks of the prior art described above.

Various other objects of the invention are apparent from the following description and from the accompanying drawings, in which FIG. 1 is a perspective view of the head section of a toothbrush, including the bristles, embodying the present invention;

FIG. 2 is a perspective view of the head section of the toothbrush of FIG. 1, but shown on a larger scale and without the bristles;

FIG. 3 is a top plan view of the head section of the toothbrush shown in FIG. 2; and

FIG. 4 is a side view of the head section of the toothbrush shown in FIG. 1.

Referring to the drawings, the toothbrush of the present invention may be of the electric type or of the handoperable type, and comprises a handle and a head 11. The toothbrush is made in one piece from plastic material which lends itself to manufacture by injection or compression molding, or by any of the procedures known for making shaped plastic objects. A polyolefin, such as polypropylene, may be employed.

The toothbrush head 11 consists of a plurality of bristle-carrying sections or segments 12, 13, 14, 15 and 16 which conjointly have a generally rectangular outline tapering slightly towards its outer end in spatulated form, as shown in FIG. 3, and separated but connected by articulating webs 17, 18, 19 and 20 which are integral with said sections. These bristle-carrying sections 12-16 have holes 21 into which bristle tufts 22 are firmly anchored in any suitable manner, well-known in the art.

Although the handle 10 is substantially rigid, the articulating webs 17, 18, 19 and 20 are thin enough to form flexible joints between brush segments 12, 13, 14, 15 and 16 and to bend when the brush head 11 is pressed against the teeth during brushing. This flexing operation causes the segments 12, 13, 14, 15 and 16 to assume such relative angularity as to cause the brush head 11 to curve, so that the bristles 22 will conform substantially to the contour of the teeth. The brush head 11 will thereby reach all parts of the teeth, including those parts of the teeth which are usually inaccessible and difficult to clean with the standard rigid brush head.

The bending moment on the webs 17, 18, 19 and 20 vary according to the distance of these webs from the outer end of the brush head. For example, when the brush is used, the bending moment on the innermost web 17 is the greatest and if these webs were all equally dimensioned, the angularity between the segments 12 and 13 would be greater than the angularity between any other two adjoining segments, the angularity between the segments 13 and 14 would be the next largest etc. As a result, the brush head 11 would not bend uniformly. Moreover, the material fatigue on the webs 17 to 20 would vary, the greatest fatigue being on the innermost web 17 and decreasing as the webs approach the outer end of the brush head 11.

To eliminate the drawbacks described, the thicknesses and the widths of the webs are relatively dimensioned to retain a predetermined pattern of flexing and fatigue. In the specific form of the invention disclosed, the relative thicknesses and widths of webs are such as to attain uniformity in bending along the length of the brush head 11 upon application of bending pressure on the outer end of the brush head, i.e. the angularity between any two adjacent segments 12 to 16 is substantially the same as the angularity of any other two adjacent segments, and the fatigue on the material of the webs 17 to 20 is consequently similarly substantially equalized.

To attain the objectives indicated, the thicknesses of the connecting webs 17 to 21 increase progressively from the outer end of the brush head 11 towards the handle 10. In addition, the spaces between the segments 12 to 16 decrease in size progressively from the outer end of the brush head towards the handle 16. As a result, the innermost web 17 which is the thickest and the narrowest of the webs has the greatest rigidity and, notwithstanding the fact that it is subjected to the greatest bending moment, will not flex to a substantially greater degree of angularity than will the other webs; the preceding web 18 is the next to the thickest and next to the narrowest and withstands the next to the biggest bending moment applied to the brush head, but it will not flex to any degree of angularity substantially different from that to which the other webs will flex; the other two webs 19 and 20 decrease in thickness and increase in width, so that the web 20 will be the thinnest and widest.

A preferred form of toothbrush head which will acone face of the segments 12, 13, 14, 15 and 16 to the other of .234 inch. Segments 13, 14 and 15 may be .234 inch wide (dimensiona) .and end egmentldmaybe .375 inchwide. In a toothbrush head so dimensioned, web 17 may be .015 inch wide (dimension b) and .045 inch thick (dimension 7); 18 may be .017 inchwide (dimension and .035 inch thick (dimension g); web 19 maybe .019 inch wide (dimension d) and .025 inch thick (di-:

mension l2) and web 20 may be .021 inch wide (dimension e) and .020 inch thick (dimension i). In this form of the invention, the Webs all havelengths which are substantially the same as the adjacent bristle-carrying sections which they connect. e v I V In another form of the invention, the lengths of the webs may be less than the lengths of the adjacent bristlecarrying sections which they connect. For example, if the lengths of the webs are made two-thirds of the length of the adjacent bristle-carrying sections, their thicknesses may be increased while still,retaining the'uniformity of bend desired throughout the head of the. brush. By appropriate selection of the dimensions ofthe various webs, the desired feature of uniformity of bending may be achieved. g

While the invention has been described with particular reference to a specific embodiment, it is tobe understood that it is not to be limited thereto and that variations and modifications may be made while remaining within the spirit of the invention.

What is claimed is: V

1'. A brush comprising an articulated head and an elongated handle connected thereto at one end, said brush head being made in one piece of flexible plastic material and comprising'a plurality 'of bristle-carrying.sections spaced apart in the longitudinal direction of said brush by integral, flexible webs which are relatively variably dimensioned by being of a length substantially equal to the adjacent bristle-carrying sections which they connect while being of increasing thicknessprogressively from the outer end of the brush head to the handle. 7 7

2. A brush as described in claim 1 wherein the thicknesses of the websincrease'progressively by substantially equal increments. r

3. A brush, comprising an articulated head and an elongated handle connected thereto at. one end, said brush head being made in one piece of flexible plastic material and comprising a plurality of bristle-carrying sections spaced apart in the longitudinal ,direction' of said brush by integral, flexible webs which are relatively variably dimensioned by being of a length substantially equal to the adjacent bristle-carrying sections which they connect While being of decreasingwidth progressively from the outer end of the brush head to the handle. V

4. A brush as defined in claim 3 wherein the widthsof the Webs decrease progressively by substantially equal increments.

adjacent bristle-carrying sections which they connect while being of increasing thickness and of decreasing width progressively from theouter end of the brush head to the handle.

6. A brush as .definedin claim 5 wherein the thick nesses of the webs increase progressively and the widths of the Webs decrease progressively by substantially equal increments respectively.

7. A brush comprising an articulated head and an elongated handle connected thereto at one end, said brush head being made in one piece of flexible plastic material and comprising a plurality of bristle-carrying sections spaced apart in the longitudinal direction of said brush by integral, flexible webs which'are'relatively variably'dimensioned by being of 'substantially'equal length which is shorter than the adjacent bristle-carrying sections which they connect while being of increasing thickness progressively from the outer end of the brush head to'the handle.

8. A brush as defined in claim 7 wherein the thicknesses of the webs increase progressively by substantially equal increments. I

9. A brush comprising an articulated head and an elongated handle connected thereto at one end, said brush head being made in one pieceof flexible plastic material and comprising a plurality of bristle-carrying sections spaced apart in the longitudinal direction of said brush by integral, flexible webs which are relatively variably dimensioned by being of substantially equal length which is shorter than the adjacent bristle-carrying sections which they connect .while being of decreasingwidth progressively from the outer end of the brush head to the handle.

10. A brush as defined in claim 9 wherein the widths of the webs decrease progressively by substantially equal increments.

11. A brush comprising an'articulated headand an elongated handle connected thereto at one end, said brush head being made in one piece of flexible plastic material and comprising a plurality of bristle-carrying sections spaced apart in the longitudinaldirection of said brush by integral, flexible webs which. are-relatively variably dimensioned by being of substantially equal length which is shorter than the adjacentbristle-carrying sections which '.they connect while being of increasing thickness and of increments respectively.

5. A brush comprising. an articulated head and an decreasing width progressively fromthe outer end of the brush head to the handle. Y

12. A brush as defined in claim 11 wherein the thicknesses of'the webs increase progressively and the widths of the webs decrease progressively by substantially equal A toothbrush as defined in claim 1. A toothbrush as defined in claim 3. A toothbrush as defined inclairn 5. A toothbrush as defined in claim 7. A toothbrush as defined in claim 9. A toothbrush as defined in claim 11.

References Cited by the Examiner 'UNITED STATES PATENTS 1,928,328 9/33 Carpentier 15-167 2,676,350 4/54 Bressler 15167 2,685,703 v 8/54 Dellenbach '15-167 CHARLES A.W.1LL MUTH, Primary Examiner. 

1. A BRUSH COMPRISING AN ARTICULATED HEAD AND AN ELONGATED HANDLE CONNECTED THERETO AT ONE END, SAID BRUSH HEAD BEING MADE IN ONE PIECE OF FLEXIBLE PLASTIC MATERIAL AND COMPRISING A PLURALITY OF BRISTLE-CARRYING SECTIONS SPACED APART IN THE LONGITUDINAL DIRECTION OF SAID BRUSH BY INTEGRAL, FLEXIBLE WEBS WHICH ARE RELATIVELY VARIABLY DIMENSIONED BY BEING OF A LENGTH SUBSTNATIALLYT EQUAL TO THE ADJACENT BRISTLE-CARRYING SECTIONS THEY CONNECT WHILE BEING OF INCREASING THICKNESS PROGRESSIVELY FROM THE OUTER END OF THE BRUSH HEAD TO THE HANDLE. 